4108 Radio link critical Alarm

Description

This alarm is reported when a. Alarm occurs in the RL and does not disappear in due time (One hour). b."Allow Radio Link Critical Alarm Report" in data configuration is enabled.

Attribute

Alarm ID	Alarm Severity	Alarm Type
4108	Major	Fault

Parameters

ID	Name	Meaning
1	Site No.	Number of the site where the faulty board or module is located Value range: 0-2047
2	Board Type	Number of the type which the faulty board belongs to. 65:DTRU/GTRU/DDRM 88:DRRU 92:DRFU 96:MRRU 100:MRFU 101:GRFU 102:GRRU 151:QTRU
3	Board No.	Number of the fault board
4	PassNo	Number of the passage where the faulty board is located.
5	SubLink No.	Alarm sub-category number 255:None
6	Cell Index	Index of the cell where the board or module is located 0-2047: Cell index of the faulty cell in the data configuration 65535: None
7	Site Type	Type of the site where the faulty board is located. 12:BTS3012; 13:BTS3006C; 14:BTS3002E; 15:BTS3012AE; 16:BTS3012 II; 17:DBS3900 GSM; 18:BTS3900 GSM; 19:BTS3900A GSM;
8	RackNo	Number of the rack where the faulty board is located.
9	BoxNo	Number of the subrack where the faulty board is located.
10	SlotNo	Number of the slot where the faulty board is located.
11	Site Name	Site Name
12	Alarm Attribute	Alarm Character 0:Normal 1:Transient Count

Impact on the System

All the services on the DTRU will be interrupted upon occurrence of this alarm.

System Actions

When this alarm occurs, the system shuts off the power amplifier automatically. For the DTRU of main BCCH, DTRU mutual aid is started.

Possible Causes

Radio link prompt alarm is generated and is not cleared within the specified time (one hour by default, definable).

Procedure

Check the alarm sub-category number (Sub No.) of the "4122 Radio link prompt alarm".
1. If the Sub No. is 0, go to2.
2. If the Sub No. is 1, go to3.
3. If the Sub No. is 2, go to4.
Check whether the channel configuration and the current channel status on the BSC side are consistent with those on the BTS side.
1. Check the channel configuration on the BSC side.
2. Check the channel configuration on the BTS side.
3. Check whether the channel configuration and the current channel status on the BSC side are consistent with those on the BTS side.
  Y => Consistent. Contact Huawei Customer Service Center.
  N => Inconsistent. Go to step d.
4. Change the channel status and channel type of the BTS. Then, check whether the alarm is cleared.
  Y => The alarm is cleared. The alarm handling is complete.
  N => The alarm is not cleared. Contact Huawei Customer Service Center.
Check for the interference and improper data configuration.
1. Check the traffic measurement counters for interference.
  Y => The interference exists. Go to step b.
  N => The interference does not exist. Go to step c.
2. Contact Huawei Customer Service Center to eliminate the interference. Then, check whether the alarm is cleared.
  Y => The alarm is cleared. The alarm handling is complete.
  N => The alarm is not cleared. Go to step c.
3. Check the traffic statistics counter "Cell Performance Measurement: Random Access Performance Measurement". Check whether the difference between "Random Access Performance Measurement > Immediate Assignment Requests" and "Random Access Performance Measurement > Immediate Assignment Successes" is greater than 400.
  Y => The difference is greater than or equal to 400. You can infer that the radio link alarm is caused by the abnormal SDCCH release. Go to step b.
  N => The difference is less than 400. Go to step d.
4. Optimize the radio resource parameters that are related to random access.
  The related parameters are RXLEV ACCESS MIN, Cell Reselection Hysteresis (CRH), and TRX Static Power Level.
  
  After the parameter optimization, check whether the alarm is cleared.
  Y => The alarm is cleared. The alarm handling is complete.
  N => The alarm is not cleared. Go to step c.
5. Check whether the abnormal TCH release occurs.
  Y => Go to step d.
  N => Go to step g.
6. Handle the abnormal TRX TCH release. Check whether the alarm is cleared.
  Y => The alarm is cleared. The alarm handling is complete.
  N => The alarm is not cleared. Go to step g.
7. Reset the TRX. Check whether the alarm is cleared.
  Y => The alarm is cleared. The alarm handling is complete.
  N => The alarm is not cleared. Go to step h.
8. Replace the TRX. Check whether the alarm is cleared.
  Y => The alarm is cleared. The alarm handling is complete.
  N => The alarm is not cleared. Contact Huawei Customer Service Center.
Check the site and related engineering connections.
1. Check whether the site is a new site without subscribers.
  Y => The site is a new site without subscribers. In this case, the alarm handling is not necessary.
  N => The site is not a new site. Go to step b.
2. Check the connections between the jumper and the duplexer, between the jumper and the feeder, between the jumper and the surge protection unit, and between the jumper and the antenna.
  Y => All the connections are good. Go to step d.
  N => A connection is not secured. Go to step c.
3. Tighten the loosened connector. Then, check whether the alarm is cleared.
  Y => The alarm is cleared. The alarm handling is complete.
  N => The alarm is not cleared. Go to step d.
4. Check whether the water leaks into the connectors between the jumper and the duplexer, between the jumper and the feeder, between the jumper and the surge protection unit, and between the jumper and the antenna.
  Y => There is water leakage. Go to step e.
  
  N => There is no water leakage. Contact Huawei Customer Service Center to handle the alarm.
5. Block the cell.
6. Replace the connector where water leakage occurs and conduct waterproof protection on the new connector in compliance with related engineering standards.
7. Unblock the cell. Check whether the alarm is cleared.
  Y => The alarm is cleared. The alarm handling is complete.
  N => The alarm is not cleared. Contact Huawei Customer Service Center.